Imaging single glycans

Title

Imaging single glycans

Speaker

Dr. Kelvin Anggara (Max Planck Institute for Solid State Research, Stuttgart, Germany)

Contact

k.anggara@fkf.mpg.de

Host

Prof. Kai Huang (GTIIT, Chemistry)

Language

English

Time and Location

Mar. 21 2022, Monday, 5:00pm-6:00pm,  E510 (Education Building, 5th floor)

Abstract

Glycans (a.k.a carbohydrates) are the most abundant biomolecules on Earth – playing key roles in intercellular signaling and energy storage. Among all classes of biomolecules, structural elucidation of glycans remains a difficult task that hinders efforts to understand how glycan properties and functions emerge. Common ensemble-averaged approaches to characterize glycans are met with difficulties due to the high flexibility of glycans. We herein bypass these limitations by using scanning tunneling microscopy (STM) to image single glycan molecules on surface, landed using electrospray ion-beam deposition (ES-IBD). Direct imaging of a glycan reveals how its constituent subunits connect to one another, thereby allowing glycan isomers to be differentiated visually [1]. Imaging multiple structures of a glycan reveals the range of conformations it can adopt (i.e. its conformation space) [2], allowing its mechanical flexibility to be determined at the single linkage level [3]. Our approach permits the topology, conformation space, and local flexibility to be determined for any glycan that can be electrosprayed, thereby opening new opportunities in single molecule analytical chemistry and material science.

[1]      X. Wu, M. Delbianco, K. Anggara, T. Michnowicz, A. Pardo-Vargas, P. Bharate, S. Sen, M. Pristl, S. Rauschenbach, U. Schlickum, S. Abb, P. H. Seeberger, and K. Kern, Nature 582, 375 (2020).

[2]      K. Anggara, Y. Zhu, M. Delbianco, S. Rauschenbach, S. Abb, P. H. Seeberger, and K. Kern, J. Am. Chem. Soc. 142, 21420 (2020).

[3]      K. Anggara, Y. Zhu, G. Fittolani, Y. Yu, T. Tyrikos-Ergas, M. Delbianco, S. Rauschenbach, S. Abb, P. H. Seeberger, and K. Kern, Proc. Natl. Acad. Sci. 113, e2102168118 (2021).

Biography

Dr. Anggara is a Scientific Group Leader at the Max Planck Institute for Solid State Research, working to image the structure and dynamics of complex biomolecules, such as glycans, at the single molecule level. He obtained his PhD in Physical Chemistry from the University of Toronto under Prof. John C. Polanyi, and completed his postdoctoral work as an Alexander von Humboldt Fellow at the Max Planck Institute for Solid State Research under Prof. Dr. Klaus Kern. He is an active supporter of scientific outreach events, such as the Lindau Nobel Laureate Meeting; and has deep interests in scientific communication to the public.